Henkel James S, Baldwin Michael R, Barbieri Joseph T
Medical College of Wisconsin, Department of Microbiology and Molecular Genetics, Milwaukee, WI 53151, USA.
EXS. 2010;100:1-29. doi: 10.1007/978-3-7643-8338-1_1.
Bacterial toxins damage the host at the site of bacterial infection or distant from the site. Bacterial toxins can be single proteins or oligomeric protein complexes that are organized with distinct AB structure-function properties. The A domain encodes a catalytic activity. ADP ribosylation of host proteins is the earliest post-translational modification determined to be performed by bacterial toxins; other modifications include glucosylation and proteolysis. Bacterial toxins also catalyze the non-covalent modification of host protein function or can modify host cell properties through direct protein-protein interactions. The B domain includes two functional domains: a receptor-binding domain, which defines the tropism of a toxin for a cell and a translocation domain that delivers the A domain across a lipid bilayer, either on the plasma membrane or the endosome. Bacterial toxins are often characterized based upon the secretion mechanism that delivers the toxin out of the bacterium, termed types I-VII. This review summarizes the major families of bacterial toxins and also describes the specific structure-function properties of the botulinum neurotoxins.
细菌毒素可在细菌感染部位或远离该部位对宿主造成损害。细菌毒素可以是单一蛋白质或具有独特AB结构功能特性的寡聚蛋白复合物。A结构域编码一种催化活性。宿主蛋白的ADP核糖基化是最早确定由细菌毒素进行的翻译后修饰；其他修饰包括糖基化和蛋白水解。细菌毒素还催化宿主蛋白功能的非共价修饰，或可通过直接的蛋白质-蛋白质相互作用改变宿主细胞特性。B结构域包括两个功能域：一个受体结合结构域，它决定毒素对细胞的嗜性；另一个转位结构域，它将A结构域穿过质膜或内体的脂质双层递送过去。细菌毒素通常根据将毒素分泌出细菌的机制进行分类，称为I-VII型。本综述总结了细菌毒素的主要家族，并描述了肉毒杆菌神经毒素的特定结构功能特性。
